Field of the Invention
The present invention relates to a coiled wave spring and a drag knob using the same.
Background Information
A coil spring has been used as a component of a fishing reel. For example, a drag knob of a spinning reel includes a coil spring for applying drag force. The coil spring is produced by forming a wire rod with a circular cross-section in a helical shape. Therefore, chances are that the coil spring will be bent in the radial direction when being compressed.
To prevent the aforementioned radial bending, a drag knob described in Japan Laid-open Patent Application Publication No. JP-A-2012-205517 uses a coil spring that is produced by forming a wire rod with a rectangular cross-section in a helical shape as described in Japan Laid-open Patent Application Publication No. JP-A-2002-39243 and Japan Examined Utility Model Application Publication No. JP-Y-H06-10226. It should be noted that the coil spring is called a coiled wave spring formed in a wave shape along the circumferential direction.
The aforementioned coiled wave spring expands in the radial direction when being compressed. As a result, one drawback is that a spinning reel is required to reliably produce a space to cope with the radial expansion of the coiled wave spring. It should be noted that this drawback is similarly produced even when the coiled wave spring is used for any components other than the drag knob.
It is an object of the present invention to provide a coiled wave spring that can be prohibited from expanding in the radial direction when being compressed, and further, to provide a drag knob using the same.